OTTAWA - The House of Commons has unanimously passed a motion condemning the Boston Marathon bombing and expressing condolences to the victims and their families.

The motion was presented by Ryan Leef, the Conservative MP for Yukon who ran in yesterday's race and was just blocks from the scene when the bombs went off.

Unanimity is a rarity in the fractious Commons and Leef says he is pleased with the co-operation..

The motion reads: "That this House condemn the attacks perpetrated during the 2013 Boston Marathon and express its deepest sympathies to the victims of this senseless violence and to their families."

The MP says he had just finished the race and was being shepherded away from the finish line by officials when the explosions came.

He said he didn't hear the blasts over the other noise around him.

"I had finished and was about three blocks up, four blocks up in the finishing corrals ... when the explosions went off," he said. "I didn't hear the explosions. There was half a million spectators cheering and PA systems going off and music, so I didn't hear that."

The 39-year-old former Mountie only realized something was wrong when he saw police and paramedics running past.

"They were coming from all directions, just racing to the finish line."